Cranes are commonly used for hoisting construction material and equipment at construction sites. Typically, cranes are limited to locations where there is a free vertical line between the hook of the crane and the location where the lifted load is placed.
At some construction sites there may be a need to place a load on a floor where a ceiling to that floor or other such obstruction exists, such as in a building. In such a case, it may be beneficial to lift the load vertically by the crane, and then shift the load sideways, horizontally, into the building, through the space formed between the floor and the associated ceiling.
U.S. Pat. No. 7,017,963 to Setzke et al. discloses a counter weighted lifting beam for enabling the lifting task described above, wherein a counterbalanced lifting beam is designed to lift and permit balancing of heavy loads. The lifting beam includes an internal counterweight that is adapted to be hydraulically adjusted by use of a manually operated control mechanism. The lifting beam also includes a rigid elongated lifting tower.
It is an object of the present invention to provide a lifting beam that may be easily adjusted to lift various loads that have significantly different weights.
It is a further object of the present invention to provide a lifting beam designed to eliminate or at least reduce the chance of the beam turning over when the beam carries an unbalanced load.